The developmental origins of health and disease theory suggests that experiencing malnutrition early in life increases the risk of chronic diseases such as obesity, diabetes, and cardiovascular disease in adulthood, and that the effects can last even for several generations. Therefore, nutritional status during pregnancy is directly related to maternal and offspring health. Malnutrition includes both under- and over-nutrition. Nutritional education and treatment of pregnant women according to scientific and standardized dietary guidelines is the joint responsibility of obstetricians and nutritionists. Nutritional support treatment during pregnancy starts with ensuring reasonable weight gain of the pregnant woman and the fetus. In addition, blood glucose, urine glucose, and urine ketone body status should be tested. Many pregnant women with newly diagnosed gestational diabetes control their own diet, but in the wrong way, resulting in no weight gain, starvation ketosis, and even hypoglycemia. Prolonged ketosis and hypoglycemia can also be very harmful to the development of the fetus. Each pregnant woman has different pre-pregnancy weight mass, blood glucose status and lifestyle, so while adhering to the basic dietary principles, they should also follow individualized principles.